i buy coffee , usually egberts mild coffee ,not rich blend. so the granules are a light caramel colour right ? so i put them into a coffee jar , ceramic jar ive had for years, after about 1 week the coffee grnaules start to stick to bottom, go darker in colour and taste not the same as first bought , they actually taste stronger/richer. i was wondering why this is happening, it never happened before. no holes or cracks in the ceramic jar at all. i thought water vapour from nearby kettle getting into jar but dont htink so....
sounds as though there's some moisture got in from somewhere if the granules have gone sticky -(wet spoon maybe/cannister not dried thoroughly and this may have affected the colour but have no idea why.
Yes, Mikey4444 is spot on. The most common type of coffee this happens to is usually the "gold" type which are freeze-dried. I've had it happen to Gold Blend and the Aldi equivalent. Your Douwe Egberts mild is freeze dried.
As Mikey says, don't decant it into another container and make sure the lid on the jar is screwed tight at all times.
All of these instant granulated foodstuff are whats called anhydrous, ie no water which means that any tiny amounts of water vapour will be absorbed by the foodstuff instantly